JP2001264667A - Optical scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical scanning device which can realize the miniaturization of the whole device, the weight saving and the low power consumption. SOLUTION: A moving part 14 is supported by an oscillating shaft 13 of a fixing part 12, and a light-emitting part 15 and a light receiving part 16 are disposed along an axis line of the oscillating shaft 13 on an upper surface of the moving part 14. The alternating current is supplied to a coil 20 provided in the moving part 14, the moving part 14 is made to oscillate in a prescribed period around the oscillating shaft 13 by the electromagnetic force which the coil 20 receives from a magnetic circuit consisting of a yoke 18 on the fixing part 12 and a permanent magnet 19. A laser beam L emitted from the light- emitting part 15 scans a bar code 4 and reads the bar code 4 in response to a reflected light L' by the light receiving part. By this configuration, the miniaturization of the device, the weight saving and the low power consumption are realized while preventing deterioration in receiving efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device applied to, for example, a bar code reader and an optical pickup of an optical disk device.

[0002]

2. Description of the Related Art FIG. 9 shows an outline of a conventional optical scanning device applied to a bar code reader. In the optical scanning device, the laser light L emitted from the light emitting unit 1 is
The light passes through a condenser lens 2 to a mirror 3, where the light path is changed to irradiate a bar code 4 which is an object to be irradiated. The light path of the reflected light from the bar code 4 is converted again by the mirror 3 and received by the light receiving unit 6 via the condenser lens 5.

A drive rod 8a of a drive unit 8 composed of an electromagnet that swings the mirror 3 at a predetermined cycle in a direction indicated by an arrow A with the swing shaft 7 as a fulcrum is fixed to the mirror 3.
Therefore, the laser beam L projected toward the mirror 3 is scanned over the entire bar code 4, and the bar code 4 is read by receiving the reflected light at the light receiving section 6.

[0004]

However, in the conventional optical scanning device configured as described above, for example, between components such as between the light emitting unit 1 and the mirror 3 or between the mirror 3 and the light receiving unit 6. Requires a certain amount of space, and there is a limit in reducing the size of each component to reduce the size of the entire apparatus. In particular, in order to efficiently receive the reflected light from the bar code 4, it is necessary to make the condensing lens 5 relatively large as shown in the figure, so that a large installation space for the condensing lens 5 must be secured. .

In recent years, optical scanning devices have been applied in a wide range of application fields, but there is a high demand for low power consumption, and therefore, there is a strong demand for miniaturization of the entire device.

The present invention has been made in view of the above problems, and has as its object to provide an optical scanning device capable of reducing the size, weight, and power consumption of the entire device.

[0007]

In order to solve the above-mentioned problems, the present invention provides a movable part provided with a light-emitting part and / or a light-receiving part for receiving reflected light of light from the light-emitting part; A driving unit that swings the movable unit and scans the laser beam, wherein the light emitting unit and / or the light receiving unit are provided on the same surface of the movable unit, and It is characterized in that it is arranged along the swing axis of the movable part.

That is, the light emitting section and the light receiving section are provided directly on the movable section to reduce the size of the apparatus. In addition, the light emitting section and the light receiving section are arranged on the same surface of the movable section, and are arranged along the swing axis of the movable section, thereby improving the light receiving efficiency of the light receiving section.

In order to solve the above-mentioned problems, the present invention has a swing axis, and while oscillating around the swing axis, directs the optical path of the light from the light emitting unit to the object to be irradiated.
An optical path conversion surface for receiving reflected light from the irradiated object;
A light receiving section for receiving the reflected light is provided on the optical path conversion surface.

That is, the invention of claim 6 aims at improving the light receiving efficiency while reducing the size of the device by omitting the installation space for the light receiving section.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, a case will be described in which the optical scanning device according to the present invention is applied to a barcode reader.

FIGS. 1 and 2 show an optical scanning device 11 according to a first embodiment of the present invention. A movable portion 14 is swingably supported by a fixed portion 12 fixed to a casing (not shown) via a swing shaft 13 provided integrally with the fixed portion 12. On the upper surface of the movable section 14, a substrate 17 on which a light emitting section 15 and a light receiving section 16 which are, for example, a light emitting element and a light receiving element are mounted in the same plane is fixed. The light emitting unit 15 and the light receiving unit 16 on the substrate 17 are arranged close to each other along the axis of the swing shaft 13 that passes through the inside of the movable unit 14.

The fixed part 12 having the axis of the swing shaft 13 as a boundary
U-shaped yokes 18, 18 are installed on both sides. A permanent magnet 19 is integrally fixed to the inner surface of the outer wall of each yoke 18.
Movable part 1 so as to pass through a magnetic circuit composed of
The coil 20 wound around 4 is located. The drive unit according to the present invention is configured by the yoke 18, the permanent magnet 19, and the coil 20.

The wiring between each element of the light emitting section 15 and the light receiving section 16 and the substrate 17 is made by a bonding wire, not shown. Further, a lens for condensing light is provided integrally with each of the elements 15 and 16 or between the light emitting and receiving light paths, but is not shown. Further, although not shown, damping means for controlling resonance of the movable portion 14 is provided.

The optical scanning device 11 of the present embodiment is configured as described above, and the operation will be described next.

When an alternating current is passed through the coil 20, the coil 2
0, each yoke 18 and permanent magnet 1
An electromagnetic force (Lorentz force) acting in the opposite direction acts from the magnetic circuit composed of
Swinging around the fixing portion 12 around. The swing cycle of the movable section 14 is determined by the AC frequency (about 40 Hz in the present embodiment) that is supplied to the coil 20.

At the same time, the laser light L
Is emitted, the laser beam L is scanned over the entire barcode 4 located above. The scanning area of the laser beam L is adjusted by the swing angle of the movable section 14 with respect to the fixed section 12. The reflected light of the laser beam L applied to the bar code 4 is received by the light receiving unit 16 on the oscillating movable unit 14, whereby a signal corresponding to the bar code pattern is read.

At this time, the light receiving section 16 and the light emitting section 15 always face the direction of the bar code 4 to be irradiated with the laser light L, so that the reflected light of the laser light L from the bar code 4 is efficiently received. can do. Further, since the light emitting unit 15 and the light receiving unit 16 are arranged along the swing axis of the movable unit 14, the displacement of the optical axis between the light emitting unit 15 and the light receiving unit 16 due to the swing angle can be minimized. Light can be received more efficiently.

Further, by disposing the light emitting section 15 and the light receiving section 16 close to each other, not only the light receiving efficiency of the principal ray is improved, but also the influence of noise components such as disturbance light and stray light is reduced. As a result, the light receiving efficiency can be improved. Therefore, when an optical composite element in which the light emitting unit 15 and the light receiving unit 16 are integrated is used, the above-described effect is enhanced.

As described above, according to the present embodiment, the light-emitting unit 15 and the light-receiving unit 16 are directly mounted on the movable unit 14 to reduce the size of the device, and reduce the weight and power consumption of the device. In addition to reducing the size of the device, it is possible to prevent a decrease in light receiving efficiency.

FIGS. 3 and 4 show a second embodiment of the present invention. In the drawings, parts corresponding to those in the above-described first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The light scanning device 21 according to the present embodiment has a light emitting unit 1 on a glass substrate 22 as a fixed unit.
5 and the silicon substrate 23 on which the light receiving section 16 is mounted. The silicon substrate 23 has a slit 25 formed by using a known etching technique, and a region inside the slit 25 is a movable portion 24. The light emitting section 15 and the light receiving section 16 are mounted on the movable section 24.

The movable portion 24 is supported by a silicon substrate 23 on the outer side of a slit 25 integrated with the glass substrate 24 via bridging portions 24a, 24a provided at two opposing peripheral edges thereof. , With a predetermined gap 26 therebetween. The electrode section 2 is opposed to the lower surface on both sides of the movable section 24 bordering a straight line connecting the bridge sections 24a, 24a.
7 a and 27 b are formed on the glass substrate 22.

Therefore, these electrode portions 27a, 27b
By applying a voltage periodically while changing the polarity, a straight line connecting the bridging portions 24a, 24a is used as an oscillation axis by an electric force (Coulomb force) between the movable portion 24 and the back surface. The swinging operation of the movable portion 24 can be obtained.

As described above, in the present embodiment, while obtaining the same operation as that of the above-described first embodiment, the entire device is further reduced in size, further reducing the overall weight of the device and reducing power consumption. Can be achieved. In particular, in the present embodiment, the semiconductor device can be manufactured with high precision by a series of semiconductor processes.
An ultra-small optical scanning device having a side of about 2 mm square can be obtained.

FIG. 5 shows a third embodiment of the present invention. Optical scanning device 31 in the present embodiment
Has a structure in which the configuration of the light receiving unit is different from that of the conventional optical scanning device described with reference to FIG.

That is, the laser light L emitted from the light emitting section 32 is condensed by the condenser lens 33, reflected by the mirror 34 which is an optical path conversion surface, and irradiated toward the bar code 4. Is configured to be received by the light receiving unit 35 fixedly arranged on the mirror 34.

The mirror 34 is configured to be oscillated at a predetermined period around an oscillating shaft 36 in a direction indicated by an arrow A in the figure by a driving rod 37a of a driving section 37 constituted by, for example, an electromagnet. As a result, the laser light L from the light emitting section 32 is scanned over the entire bar code 4. At this time, return light corresponding to the shading pattern of the bar code 4 is received by the light receiving unit 35, and the bar code 4 is read.

According to the present embodiment, the installation space related to the reception of the laser scanning light L can be made as small as possible, so that the whole apparatus can be made smaller than before and the light reception efficiency can be improved. Can be planned.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these embodiments.
Various modifications are possible based on the technical idea of the present invention.

For example, in the first embodiment described above, the light emitting unit 15 and the light receiving unit 16 are configured to swing by supporting the movable unit 13 via the swing shaft 13 provided on the fixed unit 12. However, instead of this, a configuration as shown in FIGS. 6A and 6B may be adopted.

That is, in the configuration example shown in FIG. 6A, the lower surface of the substrate 17 provided with the light emitting section 15 and the light receiving section 16 is attached to the movable end 41a of the flexible hinge member 41 made of synthetic resin.
The movable end 41a is swung via the hinge 41c with respect to the fixed end 41b of the hinge member 41 by the action of the above-described drive unit including the yoke 18, the permanent magnet 19, and the coil 20. Like that. The fixed end portion 41b of the hinge member 41 is a cylindrical casing 4 having an inner diameter of, for example, about 12 mm for accommodating the optical scanning device.
4 is fixed to the mounting base.

On the other hand, in the configuration example shown in FIG.
5 and a pair of movable ends 4 of a flexible hinge member 47 made of synthetic resin.
7a, and by the action of the above-described drive unit including the yoke 18, the permanent magnet 19, and the coil 20, the fixed end 47b common to the pair of movable ends 47a is
The movable end 41a swings through the hinge 47c.

By adopting the above configuration,
Since the entire driving section is configured to swing together with the substrate 17, a space for swinging the coil 20 in the yoke 18 is not required, and the entire apparatus is further reduced in size as compared with the first embodiment. be able to. Also, the substrate 17
Is fixed directly to the movable single parts 41a, 47a of the hinge members 41, 47, so that no special processing is required.

In the second embodiment described above, the swinging operation of the movable portion 24 with respect to the glass substrate 22 is obtained by utilizing the electrostatic force between the two. 7A and 8B can be adopted.

That is, in the configuration example shown in FIG. 7A, the electric wiring 51 is spirally formed in the plane of the movable portion 24 by a known semiconductor process technique, and is not shown but is similar to that of the first embodiment. Bridge 24a, 24a
And a drive unit for generating a magnetic field in a direction perpendicular to a straight line connecting the bridges 24a and 24c. Is made to swing.

On the other hand, in the configuration example shown in FIG. 7B, the piezoelectric member 52 is fixed to the back surface of the glass substrate 22, and the vibration from the piezoelectric member 52 is applied to the movable portion 24 through the glass substrate 22 so that the movable portion 24 is formed. It is configured to swing at a predetermined resonance frequency.

Either of these configurations can provide the same functions and effects as those of the second embodiment. In each of the above configuration examples, the bridging part 2 of the movable part 24 is used.
Although the position at which 4a is provided is different from that of the second embodiment, it suggests that any configuration may be adopted. Further, although illustration of the light emitting unit 15 and the light receiving unit 16 is omitted in the figure, similar to the above-described second embodiment,
It is assumed that they are arranged on the same surface of the movable part 24 and along the axis of the swing shaft.

Further, the second embodiment described above and FIG.
7A, the wirings for the light emitting unit 15 and the light receiving unit 16 and the electric wiring 51 for swing drive shown in FIG.
Is routed from the outside of the device, but the routing of the wiring is performed via the bridging portions 24a, 24a of the movable portion 24. 8A and 8B show an example of forming a wiring in the bridge portion 24a. That is, FIG. 8A shows a configuration example in which various wiring portions 53 are formed in a single layer in parallel, and FIG. 8B shows a configuration example in which various wiring portions 53 are formed in a multilayer. In addition, a configuration obtained by combining the two configuration examples is naturally applicable.

Next, in each of the above embodiments, the light emitting section 15 and the light receiving section 16 are attached to the movable section as separate components. However, the light emitting section and the light receiving section are mounted on the movable section. May be integrally formed using the semiconductor process technology described above. In this case, since the positional accuracy of the light emitting portion and the light receiving portion can be obtained with high accuracy at the stage of forming the movable portion, there is no need for optical alignment adjustment, and the manufacturing cost is reduced by simplifying or eliminating the post-process. Contributes to the reduction of

When the above configuration is applied to the third embodiment, the entire mirror, which is an optical path changing unit, can be configured as a light receiving unit. Thereby, the light receiving efficiency can be further improved. In this case, a conversion surface such as a mirror surface may be applied so that the entire light receiving surface can convert the optical path of the laser light L.

Further, in the above-described first and second embodiments, both the light emitting section 15 and the light receiving section 16 are provided on the movable sections 14 and 24, but either one of the light emitting section 15 and the light receiving section 16 is provided. May be provided, and the other may be separately provided.

Finally, in each of the embodiments described above, a bar code reader is described as an example of the optical scanning device. However, the present invention is not limited to this, and it is needless to say that a known optical reading mechanism (optical pickup) for an optical disk and optical communication The present invention can be effectively applied to an optical scanning mechanism for a stationary or moving object to be irradiated, such as an adjusting mechanism for a vehicle, or an inter-vehicle distance adjusting mechanism or an obstacle detecting mechanism for an automobile. .

[0044]

As described above, according to the optical scanning device of the present invention, the whole device can be made smaller than before, and
The degree of installation of the device can be liberalized, and the cost, weight, power consumption, and performance of the entire device can be reduced.

According to the second aspect of the present invention, a swinging mechanism for the movable portion can be obtained with a simple configuration, which contributes to a reduction in the cost of the entire apparatus.

According to the third aspect of the present invention, the optical scanning device can be easily formed as a swing axis of a minute optical scanning device which can be manufactured by a semiconductor manufacturing process, which greatly contributes to downsizing of the device.

According to the fourth aspect of the present invention, a swing mechanism for the movable portion can be easily obtained without requiring special processing for the movable portion.

According to the fifth aspect of the present invention, it is possible to obtain a small-sized and low-power-consumption drive unit for each swing mechanism configured as described above.

According to the sixth aspect of the present invention, it is possible to contribute to the downsizing of the device without securing a large installation space for the light receiving section and without lowering the light receiving efficiency.

According to the seventh aspect of the present invention, the light receiving efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical scanning device according to a first embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a perspective view of an optical scanning device according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along the line [4]-[4] in FIG.

FIG. 5 is a schematic configuration diagram of an optical scanning device showing a third embodiment of the present invention.

FIGS. 6A and 6B are perspective views each showing a modification of FIG. 1;

FIGS. 7A and 7B are perspective views each showing a modification of FIG. 3, in which A shows a swing mechanism by an electromagnetic force, and B shows a swing mechanism by the vibration of a piezoelectric body.

FIG. 8 is a perspective view schematically showing a wiring structure according to a second embodiment of the present invention, wherein A shows a single-layer parallel formation;
B indicates the formation of a multilayer single row.

FIG. 9 is a schematic configuration diagram showing a conventional optical scanning device.

[Explanation of symbols]

4 bar code (object to be irradiated), 11, 21, 31 optical scanning device, 12, 22 fixed unit, 13, 36 swing axis, 14, 24 movable unit, 15, 32 light emitting unit, 1
6, 35: light receiving section, 24a: bridge section, 27a, 27b ...
Electrodes, 34: mirror (optical path conversion unit), 37: drive unit, 4
1, 47: hinge member made of synthetic resin.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 31/12 H01L 31/12 E // G07G 1/00 311 G07G 1/00 311E F-term (reference) 2H045 AB03 AB73 AG06 BA02 DA02 3E042 BA17 5B072 AA03 AA06 CC24 JJ10 LL01 LL11 LL18 5F089 BA04 BA05 BB02 BC11 CA03 CA20 GA01 GA10

Claims (7)

[Claims] 1. An optical scanning device which scans light from a light emitting unit toward an object to be irradiated and obtains information by receiving the reflected light at a light receiving unit, wherein the light emitting unit and / or the light receiving unit is provided. A fixed portion that swingably supports the movable portion; and a drive portion that swings the movable portion. The light emitting unit and / or the light receiving unit are disposed on the same surface of the movable portion. An optical scanning device, wherein the optical scanning device is arranged along a swing axis of the movable portion with respect to the fixed portion. 2. The optical scanning device according to claim 1, wherein the movable section is supported via a shaft provided on the fixed section. 3. The movable part is disposed to face the fixed part with a predetermined gap therebetween, and is supported by the fixed part via two peripheral edges of the movable part. The optical scanning device according to claim 1. 4. The optical scanning device according to claim 1, wherein the movable portion is supported by the fixed portion via a flexible hinge made of synthetic resin. 5. The device according to claim 1, wherein the driving unit includes a magnetic field generating unit configured to generate a magnetic field in a direction perpendicular to a swing axis of the movable unit, and a coil provided in the movable unit so as to cross the magnetic field. The optical scanning device according to claim 1, wherein 6. An optical scanning device which scans light from a light emitting section toward an object to be illuminated, receives the reflected light at a light receiving section and obtains information, and has an oscillating axis. While swinging the light path of the light from the light emitting unit to the irradiation target,
An optical scanning device comprising: an optical path conversion surface that receives light reflected from the irradiation object; and the light receiving unit is provided on the optical path conversion surface. 7. The optical scanning device according to claim 6, wherein the optical path conversion surface is formed by a light receiving surface of the light receiving unit.